Binary Stumble

an artist's adventures in the digital world

Another New Garmin Etrex

Garmin eTrex 10 and Garmin SE side by side on a brown wood table

So my latest Garmin eTrex 10 broke in the same way the previous ones did: the rubber round the power button either degrades or gets thin and drops out. Then the side of the circuit board is exposed through the little hole it leaves, revealing a tiny push button that I then have to use my keys or the arms of my glasses or a pen to push to turn it on and off. This finally failed the other day and I could no longer turn it on.

Time for a new one I thought. We’ve been buying Garmin eTrex 10s since 2012. I wrote about them here, 13 years ago. They’ve been part of our daily lives and our long term project of capturing everywhere we go, every day since then.

Visiting the Garmin site, I realised they had been discontinued and replaced with what they called an eTrex SE. This now seems to be Garmin’s entry level GPS model. After checking that it would mount as an external drive without the need to install funky proprietary software, I ordered one, which duly arrived.

Teething troubles

The USB interface on the eTrex SE is now USB C, so I plugged one in and nothing happened (on my laptop at least). I tried it on Soph’s Carbon X1 running Debian with Cinnamon desktop environment and it mounted as an MTP device(?) This was good, I thought. But I was faced with a list of files and folders which I didn’t recognise from the etrex 10. There seemed to be lots of ‘.fit’ files in dozens of different folders. I intuited that there might be some interest in the ‘Activities/Track Me’ folder. I’d had to set that in the GPS. The ‘.fit’ files in this folder are the ones that contain the tracks I’m recording.

A new file format

The fit files are a binary format but luckily there are some options.

GPSBabel reads them and can generate a GPX file out of them but they come in as one long track / track segment rather than being split up in the way that the eTrex 10 used to do automatically when you plugged it in to a computer. You can get GPSBabel to make new tracks every time it detects a gap of a certain number of seconds between points. I favour 60 seconds for this. I also like each track to be named after the timestamp of the first trackpoint. The command for all this is gpsbabel -t -i garmin_fit -f [path-to-fit-file.fit] -x track,pack,split=60s,title="%Y-%m-%dT%H:%M:%S" -o gpx -F [name-of-gpx-file-you-want-to-save.gpx]

The other option is to install the python package garmin-fit-sdk with pip or your installer of choice and roll your own converter script, which is what I did. There are a couple of details to deal with. Garmin-fit-sdk brings in all timestamps as timezone aware (at least that!) datetime objects, like datetime.datetime(2025, 10, 18, 16, 12, 35, tzinfo=datetime.timezone.utc) and you’ll need to write that as the string "2025-10-18T16:12:35Z" in your GPX file. The other is that the fit file (or you could say the Garmin) saves the latitutde and longitude in a semicircle format, expressed as a nine digit number. To convert this into degrees, you times it by 180 / 231. I’ve yet to see what happens to my script when the longitude crosses the zero meridian and goes negative. Let’s hope it copes, because having dyscalculia, I don’t have the maths to troubleshoot it!

Preliminary Cons

I say ‘preliminary’ because it’s a little early to tell. It took years to develop the work flow with the eTrex 10s, involving an import script and preprocessing script before manual editing and finally importing into the sqlite database (with the Spatialite extension).

  • No GPX file made
  • New fit file format I have to re-write my importing process for
  • No track segments
  • No idea when I’m running out of memory
  • Not sure whether leaving the GPS on but not moving (like when we’re in the garden, or working outside), keeps recording. This could be a deal breaker for us, because of our birch forest visualisations and carpets.
  • As you can see in the photo, it’s bulkier. It’s not quite as thick as the eTrex 10 but it is taller and wider.

Preliminary Pros

  • They are being produced, unlike eTrex 10s now.
  • Battery life seems better.
  • It is harder to make random waypoints (the prominent button on the front of the eTrex 10 used to be pressed in bags etc and result in random waypoints being generated).

Conclusion

I’m a little skeptical and the not recording while stationary might be a deal breaker, as I say, but I will give it a go and see if we can make it work. Otherwise, we’re in to hardware hacking to repair the old ones or building our own, which won’t be as durable.